I think even now it being centralized but not by a single person or any private holders. If this could happen, then there would be a massive change and a big impact to the whole economy of bitcoin. The value of it could have boundaries. They could imploy not to take a huge amount of it. But for somehow they could simply protect it and lengthen the possibility of losing bitcoin. Then, making bitcoi centralized could give a disadvantage and somehow advantage on it.
Centralized bitcoin would have been limited to certain class and there had been cases of corruption in this currency as well. It is loved by people because everyone owns it. No one can stop others from using it or can claim it as his or her property.